Method for fabricating light emitting device and method for fabricating liquid crystal display device

ABSTRACT

The object of the invention is to provide a method for fabricating a semiconductor device having a peeled layer bonded to a base material with curvature. Particularly, the object is to provide a method for fabricating a display with curvature, more specifically, a light emitting device having an OLED bonded to a base material with curvature. An external force is applied to a support originally having curvature and elasticity, and the support is bonded to a peeled layer formed over a substrate. Then, when the substrate is peeled, the support returns into the original shape by the restoring force, and the peeled layer as well is curved along the shape of the support. Finally, a transfer object originally having curvature is bonded to the peeled layer, and then a device with a desired curvature is completed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/422,980, filed Jun. 8, 2006, now U.S. Pat. No. 7,446,339, which is acontinuation of U.S. application Ser. No. 11/079,287, filed Mar. 15,2005, now U.S. Pat. No. 7,060,591, which is a continuation of U.S.application Ser. No. 10/334,076, filed Dec. 27, 2002, now U.S. Pat. No.6,953,735, which claims the benefit of a foreign priority applicationfiled in Japan as Ser. No. 2001-402016 on Dec. 28, 2001, all of whichare incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a method for fabricating asemiconductor device having a circuit configured of a thin filmtransistor (hereafter, it is called a TFT) in which a peeled layer thathas been peeled is bonded and transferred to a base material,particularly to a method for transferring a circuit configured of a TFTto a support with curvature.

In recent years, a technique has been receiving attention in which asemiconductor thin film (a thickness of about a few to a few hundredsnanometers) formed over a substrate having an insulated surface is usedto configure TFTs. The TFT is widely used for electronic devices such asICs and electro-optic devices, which has been urged to develop as aswitching device for image display devices.

In addition, an attempt has been made to install various display deviceson vehicles such as automobiles and aircrafts, including display devicesfor navigation systems, operation screen display devices for audiosystems, and display devices for meters.

Various applications utilizing such the image display devices areexpected, however, attention is being given to the use for portabledevices in particular. At present, glass and silica are mainly used forsubstrates, but the display devices with glass and silica substrateshave disadvantages of being thick, heavy-weight and easy to crack, whichparticularly have disadvantages for portable devices that are highlyrequired to be low-profile, light-weight and hard to crack. Furthermore,glass and silica are generally difficult to be formed into large-sizedproducts, having disadvantages for mass production in particular. Onthis account, an attempt has been made to form TFT devices on asubstrate having bendability, flexibility or elasticity, typically aflexible plastic film or sheet.

However, plastics have low heat resistance, inevitably dropping themaximum temperature in the device fabrication processes. On thisaccount, the electric characteristics of the TFTs formed on a plasticare essentially inferior to the TFTs formed on a glass substrate.Therefore, high-performance light emitting diodes and liquid crystaldisplay devices using plastics have not been realized yet.

SUMMARY OF THE INVENTION

When light emitting devices and liquid crystal display devices can befabricated, which have an organic light emitting diode formed on asubstrate with bendability, flexibility or elasticity, typically aplastic film or sheet, they can be used for displays and show windowshaving a curved surface, in addition to the characteristics of beinglow-profile, light-weight and hard to crack. Thus, the use is notlimited only to portable devices, having the wide application range.

Furthermore, in the case where displays for images and meters areinstalled in limited spaces, such as the driver seat of vehiclesincluding automobiles and aircrafts, when display devices are formed tomatch the curvatures with various curved surfaces of windows, ceilings,doors and dashboards beforehand, allowing installing them not only onthe flat surfaces but also on the curved surfaces as they are.Traditionally, the displays have had flat surfaces, causing spacesinside the vehicles to narrow or the installation work to be complexthat a wall is cut out to fit and install a flat display.

The object of the invention is to provide a method for fabricating asemiconductor device having a peeled layer bonded to a base materialwith curvature. Particularly, the object is to provide a method forfabricating a display with curvature, more specifically, a lightemitting device having an organic light emitting diode bonded to a basematerial with curvature, or a liquid crystal display device bonded to abase material with curvature.

The configuration of the invention relating to the fabrication methoddisclosed in the specification is a method for fabricating asemiconductor device including:

a first step of forming a support and a transfer object (body) withcurvature;

a second step of forming a peeled layer containing a device over asubstrate having rigidity higher than that of the support;

a third step of bonding the support with curvature to the peeled layercontaining the device and the substrate with an external force appliedso as to match the surface topology of the peeled layer containing thedevice and the substrate;

a fourth step of peeling the peeled layer containing the device bondedwith the support from the substrate by a physical unit; and

a fifth step of bonding the transfer object to the peeled layercontaining the device to sandwich the device between the support and thetransfer object,

wherein the support bonded with the peeled layer containing the devicefully or partially returns into the shape after the first step has beenfinished at the time of finishing the fourth step.

In addition, in the invention, the support is for bonding to the peeledlayer in peeling by the physical unit, which is not defined particularlywhen it has a desired curvature and elasticity, that is, the property toexert a restoring force to return to the original shape when an externalforce is applied. The base materials are fine to have any composition,including plastics, glass, metals and ceramics. Furthermore, in thespecification, the transfer object is for bonding to the peeled layerafter peeled, which is not defined in particular when it has a desiredcurvature. The base materials are fine to have any composition,including plastics, glass, metals and ceramics. Particularly, when thetop priority is weight saving, a film plastic substrate is preferable,such as polyethylene terephthalate (PET), polyether sulfone (PES),polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyetherether ketone (PEEK), polysulfone (PSF), polyetherimide (PEI),polyallylate (PAR), and polybutylene terephthalate (PBT).

Moreover, the configuration is characterized by R_(i)≦R_(f)≦R_(m), wherethe curvature radius of the support after the first step is finished isR_(i), the curvature radius after the third step is finished is R_(m),and the curvature radius after the fourth step is finished is R_(f).

Besides, the configuration is characterized in that when a lightemitting device having an organic light emitting diode is formed, thesupport is an encapsulation material and the device is a self-luminousdevice.

In addition, the configuration is characterized in that when a liquidcrystal display device is formed, the support is an opposite substrateand the device has a pixel electrode, in which a liquid crystal materialis filled between the pixel electrode and the opposite substrate.

Furthermore, the configuration is characterized in that at least one ofthe support and the transfer object is transparent.

Moreover, the configuration is characterized in that the curvature radiiof the support and the transfer object range from 50 to 200 cm.

Besides, in the configuration, the peeling method is not definedparticularly. Such methods can be used that a separate layer is disposedbetween the peeled layer and the substrate and the separate layer isremoved with a chemical solution (etchant) to separate the peeled layerfrom the substrate, and that a separate layer made of amorphous silicon(alternatively, polysilicon) is disposed between the peeled layer andthe substrate and laser light is irradiated as passed through thesubstrate to release hydrogen contained in the amorphous silicon,whereby a clearance is generated to separate the peeled layer from thesubstrate. In addition, when the laser light is used for separation,devices contained in the peeled layer are desirably formed to setannealing temperatures at 410° C. or below so as not to release hydrogenbefore peeling.

Furthermore, as another peeling method, a peeling method may be used inwhich a membrane stress between two layers is utilized for peeling. Thispeeling method can cleanly, easily separate in an oxide layer or in theinterface by a physical unit with no film removal (peeling) even throughsuch processes, in which a metal layer, preferably a metal nitride layeris deposited on a substrate, an oxide layer is further deposited on themetal nitride layer, devices are formed over the oxide layer, and thenthe deposition process or annealing at temperatures of 500° C. or aboveis performed. For further facilitating the peeling, annealing or laserlight irradiation may be performed before peeling by the physical unit.

Moreover, according to each of the fabrication methods, the display witha curved surface can be realized to allow installation in vehicles suchas automobiles, aircrafts, ships and trains. The inner walls andceilings of the vehicles have wide space as much as possible and areconfigured of smooth, curved surfaces not causing problems even thoughhuman bodies come up against them for any reason. It is also possible toinstall a display device having a TFT and an organic light emittingdiode in these curved surfaces as a meter or lighting system. Inaddition to this, the method for driving the display device having theTFT and the organic light emitting diode is preferably the active matrixtype, but it is acceptable to be the passive matrix type.

For example, the window of the vehicles is formed of a base material andthe display device having the organic light emitting diode with thecurvature matched with the curved surface of the window is bonded withno curve as it is, whereby images and meters can be displayed.Particularly, the display device having the organic light emitting diodecan be formed to be significantly light weight, and thus space is notchanged. When the display device having the organic light emitting diodeis bonded to the window of the vehicles, the substrates, electrodes andwiring lines are desirably transparent, and a film for blocking theexternal light may be provided. Furthermore, it is preferable to confirmoutside landscapes without problems when not displayed.

Moreover, along the inner walls, doors and seats of the vehicles, oralong car dashboards, the display device having the organic lightemitting diode with the curvature matched with the curved surfaces isbonded with no curve as it is, whereby images and meters can bedisplayed. It is fine only to bond the display device fabricatedaccording to the invention along the curved surface, and thus theinstallation work is significantly simple, not requiring partial work tothe inner walls, doors, seats and dashboards in particular. Besides, inthe automobiles, for example, when the car is right-handled, a deadangle exists left backside because a part of a car body (a portionbetween window glasses) is there. However, when the display devicefabricated according to the invention is installed in the portionbetween the window glasses, and a camera capable of shooting in the deadangle direction is mounted outside the car to connect them each other, adriver can confirm the dead angle. Particularly, the display devicehaving the organic light emitting diode is the display device that issuperior in moving pictures to the liquid crystal display device and hasa wider viewing angle.

In addition, the ceiling of the vehicles is formed of a base material,and the display device having the organic light emitting diodes with thecurvature matched with the curved surface of the ceiling is bonded withno curve as it is, whereby image display and lighting the inside can beperformed. Furthermore, in the automobiles, for example, when thedisplay devices fabricated according to the invention are bonded in theceiling and portions between the window glasses, and cameras capable ofshooting outside landscapes corresponding to the separate displaydevices are mounted outside the car to connect them each other, peopleinside the car can enjoy outside landscapes as if they seated in aconvertible car. Moreover, when the display device fabricated accordingto the invention is bonded to the ceiling and sidewalls in trains andelectric railcars, for example, advertisement display and televisionpictures can be displayed without narrowing the space. Particularly, thedisplay device having the organic light emitting diode is the displaydevice with a viewing angle wider than that of the liquid crystaldisplay device.

In the vehicles, when the curvature radius of the curved surface in theinstalled display device ranges from 50 to 200 cm, the TFT and theorganic light emitting diode can be driven without problems.

In addition, the semiconductor device in the invention is the devices ingeneral which can function by utilizing the semiconductorcharacteristics. The electro-optic devices, the light emitting devices,the semiconductor circuits and electronic devices are all semiconductordevices.

BRIEF DESCRIPTION OF THE DRAWINGS

The teachings of the invention can be readily understood by consideringthe following detailed description in conjunction with the accompanyingdrawings, in which:

FIGS. 1A to 1E are flow charts illustrating the invention (Embodimentmode);

FIGS. 2A and 2B are diagrams illustrating one form of plastic molding(Embodiment mode);

FIGS. 3A to 3E are flow charts of fabricating a semiconductor devicehaving an organic light emitting diode (Embodiment 1);

FIGS. 4A to 4E are flow charts of fabricating a semiconductor devicehaving liquid crystals (Embodiment 2);

FIG. 5 is a diagram of an apparatus for fabricating a semiconductordevice having an organic light emitting diode with the invention(Embodiment 3);

FIG. 6 is a diagram illustrating inside a car and around an automobilewindshield (Embodiment 4);

FIG. 7 is a diagram illustrating inside the car and around a rear window(Embodiment 4); and

FIG. 8A-F are diagrams illustrating the cross sections around TFTs andlight emitting diodes contained in peeled layers Embodiment 5).

DESCRIPTION OF THE PREFERRED EMBODIMENT Embodiment Mode

Hereafter, the embodiments of the invention will be described by FIGS.1A to 1E, and 2A and 2B, according to the typical fabricationprocedures.

FIG. 1A shows a first step of fabricating a support 111 and a transferobject 112. It is important to fabricate them to have a desiredcurvature according to the purposes, particularly to fabricate thesupport 111 to have elasticity. The curvature radius of the support 111after the first step is finished is defined as Ri. The row materials,material quality and shaping methods are not defined in particular. Thethickness is not limited in particular as well. Typically, it is fine tohave a thickness of about 100 micrometers. Generally, those having afilm thickness of 200 micrometers or below are called a film, and thoseof 200 micrometers or greater are called a sheet. It is acceptable thatthe support 111 and the transfer object 112 are a film or sheet. As forthe support 111, it is fine that the support is so thin that it haselasticity. Here, plastics are used for both the support 111 and thetransfer object 112. With the use of general thermoplastic resins orthermosetting resins as row materials, they are shaped by generalplastic molding, that is, in the course of plasticization in which a rowmaterial is heated for easy flow, shaping in which a mold is used togive a desired shape, and solidification in which the shape isstabilized by cooling or curing reaction. For example, FIGS. 2A and 2Bshow the steps of compression molding of a thermosetting resin. First,as shown in FIG. 2A, a thermosetting resin 212, which is heated withhigh flowability, is filled in a mold (female mold) 211 b. Then, asshown in FIG. 2B, a mold (male mold) 211 a is used to apply pressurefrom the direction indicated by arrows. When the molds 211 a and 211 bare heated as the pressure is held, the flowability of the resin dropsat some point for curing. Subsequently, the molds 211 a and 211 b areopened to obtain a molded product.

In addition, a coating film with various functions (not shown) can bedeposited in a single layer or multiple layers over the support 111 andthe transfer object 112. Generally, a barrier film for blocking waterand oxygen, a base film for improving the adhesion of adhesives, and aprotection layer for enhancing chemical resistance and physical strengthare laminated. For example, a silicon nitride thin film having athickness of about 100 nm can be deposited over the support 111 bysputtering. However, at least one of the support 111 and the transferobject 112 needs to have a limited light transmittance, that is, to betransparent.

FIG. 1B shows a second step of fabricating a peeled layer 121 on asubstrate 122. The peeled layer comprises various devices, typicallyTFTs (thin film diodes, and photoelectric conversion devices formed ofpin junctions of silicon junctions, and silicon resistance elements) andan organic light emitting diode, generally including electrodes, wiringlines and insulating films. The rigidity of the substrate 122 is sethigher than that of the support 111. In FIG. 1B, the substrate 122 isillustrated so as to be fully covered with the peeled layer 121 forsimplification, but it is no problem to partially expose the substrate122.

FIG. 1C shows a third step of bonding the support 111 to the substrate122 and the peeled layer 121. First, an external force is applied to thesupport 111 to shape it into a form matched with the surface topology ofthe substrate 122 and the peeled layer 121. For example, it is fine thatthe support 111 originally curved as shown in FIG. 1A is stretchedstraight and bonded as shown in FIG. 1C. After bonded, the restoringforce to return to the original shape is exerted over the support 111,but the bonded substrate 122 has higher rigidity, and thus the support111 keeps the state of being stretched straight at this stage. Morespecifically, when the curvature radius of the support 111 after thethird step is finished is defined as R_(m), the curve of the support 111becomes smoother than that after the first step is finished in general,and therefore it is generally R_(i)≦R_(m). As the bonding method, it ispreferable to closely contact the support 111 with the peeled layer 121or the support 111 with the substrate 122, but a limited space may existinside.

Types of adhesives (not shown) and the coating method are not definedparticularly. More specifically, it is acceptable that the reactivecuring type, thermosetting type, photo-curing type and anaerobic type ofadhesives are coated by techniques including screen printing, drawing bya dispenser and discharge by a spray. Here, a UV cure adhesive, which isone kind of the photo-curing type, is coated by a dispenser. Theadhesive is coated over the support 111 or peeled layer 121, and thenultraviolet rays are irradiated, whereby the adhesive is cured.Generally, the peeled layer 121 has portions to be damaged byirradiating the ultraviolet rays. Therefore, it is fine to use a properlight shielding mask for covering the portions, and alternatively toirradiate ultraviolet rays having selective energy that cures only theadhesive and does not damage the other portions, whereby damages areavoided.

FIG. 1D shows a fourth step of peeling the peeled layer 121 from thesubstrate 122. The peeling method is not limited particularly. Here, thepeeling method that utilizes the membrane stress between a metal layeror nitride layer and an oxide layer is used, which is not restricted byannealing temperatures and substrate types. First, a nitride layer ormetal layer (not shown) is deposited over the substrate 122 before thestate shown in FIG. 1B is obtained. As typical example for the nitridelayer or metal layer, it is fine to use a single layer formed of anelement selected from Ti, W, Al, Ta, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh,Pd, Os, Ir and Pt, an alloy material or compound material having aprincipal component of these elements, or a laminated layer of these,and alternatively a single layer formed of nitrides of these such astitanium nitride, tungsten nitride, tantalum nitride and molybdenumnitride or a laminated layer of these. Subsequently, an oxide layer (notshown) is deposited over the nitride layer or metal layer. As a typicalexample for the oxide layer, it is fine to use silicon oxide, siliconoxide nitride and metal oxide materials. In addition, it is fine todeposit the oxide layer by methods including sputtering, plasma CVD andcoating. The film thickness of the nitride layer or metal layer and theoxide layer is properly set within the range of 1 to 1000 nm, wherebythe membrane stress of both layers can be varied each other.Furthermore, it is acceptable that an insulating layer or a metal layeris disposed between the substrate 122 and the nitride layer or metallayer to enhance the adhesion to the substrate 122. Then, asemiconductor layer is deposited over the oxide layer to obtain thepeeled layer 121. Moreover, the peeling method does not generate filmremoval due to annealing in the fabrication process of the peeled layereven though the membrane stress of the oxide layer is varied from themembrane stress of the nitride layer or metal layer. Besides, thepeeling method allows peeling with a relatively small force because themembrane stress of the oxide layer is varied from the membrane stress ofthe nitride layer or metal layer. In addition, it is also important topay attention not to generate cracks in peeling the peeled layer 121.

As described above, the peeled layer 121 deposited over the oxide layercan be separated from the substrate 122. The important point is in thatthe support 111 returns into the original shape after the first step hasbeen finished by the restoring force at this stage. In accordance withthis, the peeled layer 121 bonded beneath the support 111 also curvesalong the support 111. When the curvature radius of the support 111after the fourth step is finished is defined as Rf, the curve of thesupport 111 becomes acuter than that after the third step is finished,that is, it becomes R_(f)≦R_(m), because the support 111 returns intothe shape after the first step has been finished. In the meantime, inaddition to which the support 111 does not have perfect elasticity ingeneral, the peeled layer 121 is bonded thereto, and thus the curvegenerally becomes smoother than that after the first step has beenfinished, that is, it becomes R_(i)≦R_(f). Accordingly, it generallybecomes R_(i)≦R_(f)≦R_(m).

FIG. 1E shows the step of bonding the transfer object 112 to the peeledlayer 121. As for the shape and thickness of the transfer object 112,they are not defined particularly when the transfer object 112 isfabricated to match the surface topology of the peeled layer 121 havingcurved in FIG. 1D in consideration of the shape and thickness of thesupport 111 and the thickness of the peeled layer 121. It is preferableto have the elasticity as similar to the support 111.

The bonding direction of the support 111 is not defined particularly inFIG. 1B. However, when a plurality of TFTs are disposed in the peeledlayer 121, it is more preferable to bond the support such that thechannel length of all the TFTs is arranged in the same direction and thechannel direction is arranged in parallel to the direction where thesupport 111 does not have the curvature in FIG. 1A. It is because theinfluence upon the TFTs in the peeled layer 121 can be suppressed to theminimum when the support 111 bonded with the peeled layer 121 returnsinto the original shape by the restoring force after the substrate 122has been peeled in FIG. 1D.

When a liquid crystal display device is fabricated, it is fine that thesupport is formed of an opposite substrate and the sealing material isused as an adhesive to bond the support to the peeled layer. In thiscase, the devices disposed in the peeled layer have pixel electrodes,and a liquid crystal material is filled between the pixel electrodes andthe opposite substrate.

Furthermore, when a light emitting device is fabricated, which istypified as a device having an organic light emitting diode, the lightemitting diode is preferably fully blocked from outside so as to preventmatters from entering from the outside with the use of the support as anencapsulation material, the matters such as water and oxygen facilitatethe degradation of an organic compound layer. Moreover, when the lightemitting device is fabricated, which is typified as a device having anorganic light emitting diode, it is preferable to sufficiently protectnot only the support but also the transfer object against matters so asnot to enter from outside, the matters such as water and oxygenfacilitate the degradation of the organic compound layer. Moreover, whenit is considered important to suppress the degradation due to thepenetration of water and oxygen, a thin film contacting with the peeledlayer is deposited after peeling, whereby cracks generated in peelingare repaired. A film having thermal conductivity is used for the thinfilm contacting with the peeled layer, specifically an aluminum nitrideor aluminum nitride oxide, whereby obtaining advantages to diffuse theheat from the devices and to suppress the degradation of the devices andan advantage to protect the transfer object, specifically a plasticsubstrate from deformation and degradation in quality. Besides, the filmhaving the thermal conductivity also has an advantage to preventimpurities such as water and oxygen from entering from outside.

As for the invention formed of the configurations will be describedfurther in detail with the following embodiments.

Embodiment Embodiment 1

In the embodiment, the procedures to fabricate a light emitting devicehaving an organic light emitting diode (OLED) are shown in FIGS. 3A to3E.

As shown in FIG. 3A, a first material layer 312 is formed over asubstrate 311. As the first material layer 312, it may have compressivestress or may have tensile stress immediately after the deposition. Itis important to use materials that do not generate abnormality inpeeling due to annealing in forming the peeled layer and the irradiationof laser light and have tensile stress in the range of 1 to 1×10¹⁰(Dyne/cm²) after the peeled layer is formed. Typically, nitrides ormetals are preferable. A representative example is a single layer formedof an element selected from W, WN, TiN and TiW, an alloy material orcompound material having a principal component of the elements, or alaminated layer of these. In addition, it is fine to use sputtering forthe first material layer 312.

For the substrate 311, glass, silica and ceramics can be used.Furthermore, it is acceptable to use a semiconductor substrate typicallysilicon, or a metal substrate typically stainless steel. Here, a glasssubstrate (#1737) having a thickness of 0.7 mm is used.

Subsequently, a second material layer 313 is deposited over the firstmaterial layer 312. As for the second material layer 313, it isimportant to use materials that do not generate abnormality in peelingdue to annealing in forming the peeled layer and the irradiation oflaser light and have compressive stress in the range of 1 to 1×10¹⁰(Dyne/cm²) after the peeled layer is formed. For the second materiallayer 313, oxides are preferable. A representative example is siliconoxide, silicon oxide nitride, metal oxide materials or a laminated layerof these. Moreover, it is fine to deposit the second material layer 313by sputtering. When the second material layer 313 is deposited bysputtering, a rare gas typically argon gas is introduced into a chamberto have a slight amount of a rare gas element contained in the secondmaterial layer 313.

In the first material layer 312 and the second material layer 313, it isacceptable that the film thickness of each layer is properly set in therange of 1 to 1000 nm to adjust the internal stress in the firstmaterial layer 312 and the internal stress in the second material layer313.

In addition, in FIGS. 3A to 3E, the embodiment is shown for simplifyingthe processes in which the first material layer 312 is formed ascontacting with the substrate 311. However, it is fine that aninsulating layer or metal layer to be a buffer layer is disposed betweenthe substrate 311 and the first material layer 312 to enhance theadhesion to the substrate 311.

Then, a peeled layer 314 a containing TFTs is formed over the secondmaterial layer 313. The peeled layer 314 a includes TFTs in a pixelportion (part) (an n-channel TFT and a p-channel TFT), drive circuitTFTs disposed around the pixel portion (an n-channel TFT and a p-channelTFT), and wiring lines. Subsequently, an insulating film for coveringeach of the TFTs is formed, and then the cathode or the anodeelectrically connected to the TFTs disposed in the pixel portion isformed. After that, an insulator called a bank is formed on both ends soas to cover the end part of the cathode or the anode. Furthermore, it isfine to properly form a passivation film (protection film) formed of anitride film so as to cover the TFTs as necessary. Moreover, as theprocess of forming the peeled layer 314 a, annealing can be performed asresistible by the substrate 311. Besides, even though the internalstress in the second material layer 313 is varied from the internalstress in the first material layer 312, annealing treatment in theprocess of fabricating the peeled layer 314 a will not cause filmremoval.

Then, a peeled layer 314 b containing an organic light emitting diode isformed over the peeled layer 314 a containing the TFTs. That is, an ELlayer (organic compound material layer) is formed over the cathode orthe anode covered with the bank. It is acceptable that the anode isdisposed over the EL layer when the under layer of the EL layer isformed into the cathode, whereas the cathode is disposed over the ELlayer when the under layer of the EL layer is formed into the anode.

As the EL layer, layers for injecting, transferring and recombiningelectron and hole carriers, that is, a light emitting layer, a carriertransport layer and a carrier injection layer are combined freely. Asthe organic EL materials, the low-weight molecular type, the polymertype and those combining both can be used. In addition, as the EL layer,such thin films can be used that the thin films are formed of lightemitting materials capable of obtaining light emission from the singletexcitation state or triplet excitation state (generally, the former isfluorescence, and the latter is phosphorescence). For film depositionmethods, the dry process such as vacuum evaporation and electron beam(EB) evaporation are general in the low weight molecular type materials,whereas the wet process such as spin coating and ink jet printing aregeneral in the polymer type materials. Furthermore, inorganic materialssuch as silicon carbide can be used as the carrier transport layer andthe carrier injection layer. For the organic EL materials and theinorganic materials, publicly known materials can be used. Moreover, theEL layer is formed into a thin film layer of about 100 nm in total. Tothis end, the surface formed as the cathode or the anode needs toenhance the flatness.

Besides, as the materials used for the cathode, it is preferable to usemetals having a small work function (alkali metals and alkaline earthmetals) and alloys containing these. For example, in the organic lightemitting diode using an aluminium alloy (AlLi alloy) containing a slightamount of Li (lithium) for the cathode, which is one of alkali metals,the light emitting characteristics are generally excellent and thereduction in luminance is small even though lighting for long hours.Alternatively, when a single metal (Al, for example) having a workfunction not so small is laminated over an ultrathin film (about onenanometer) formed of oxides and fluorides of alkali metals and oxidesand fluorides of alkaline earth metals, the excellent devicecharacteristics can be similarly obtained. For example, when thestructure is used in which Al is laminated over an ultrathin film of LiFinstead of the AlLi alloy as the cathode, the similar characteristicscan be obtained as well.

In addition, as the conductive film used for the anode, materials havinga work function greater than that of the materials for forming thecathode are used. Particularly, for transparent conductive films, thetin oxide (SnO₂) type, zinc oxide (ZnO) type and indium oxide (In₂O₃)type of materials, typically ITO (indium oxide-tin oxide alloy) and IZO(indium oxide-zinc oxide alloy) are widely used. Furthermore, materialshaving sheet resistance lower than that of ITO, specifically platinum(Pt), chromium (Cr), tungsten (W) and nickel (Ni) can be used as well.

The steps described above, the peeled layer is formed in which the layer314 b containing the organic light emitting diode is laminated with thelayer 314 a containing the TFTs to be connected to the organic lightemitting diode. Moreover, there are roughly two methods to controlcurrent carried through the organic light emitting diode by the TFTs.More specifically, a method of controlling current in the voltage rangecalled the saturation region and a method of controlling current in thevoltage range that reaches to the saturation region. In thespecification, the Vd range where the current value is nearly constantis called the saturation region in the Vd-Id curve. The invention is notlimited to the methods for driving the organic light emitting diode,which can use arbitrary driving methods.

Then, the treatment to partially reduce the adhesion of the firstmaterial layer 312 to the second material layer 313 is performed. Thetreatment to partially reduce the adhesions is the treatment that laserlight is partially irradiated onto the second material layer or firstmaterial layer along the rim of the area to be peeled, or the treatmentthat a local pressure is applied from outside along the rim of the areato be peeled and the inside or interface of the second material layer ispartially damaged. More specifically, it is acceptable that a hardneedle is pressed vertically with a diamond pen and moved with load.Preferably, it is fine that a scriber is used, an amount to press is setfrom 0.1 to 2 mm and pressure is applied to move the edge of thescriber. In this manner, it is important to create a portion where theremoval phenomenon tends to be generated before peeling, that is, tocreate a trigger. The pretreatment to selectively (partially) reduce theadhesion is performed, defects in peeling are eliminated and the yieldis enhanced as well.

Subsequently, as shown in FIG. 3B, a flexible printed circuit 321 (FPC)is bonded to a terminal electrode disposed at the end part of aninterconnect wiring line connected to the TFTs disposed in the peeledlayer 314 a.

Then, a support 323 is bonded to the peeled layers 314 a and 314 b witha first adhesive 322. The support 323 originally having curvature andelasticity is bonded with the external force applied. After bonded, therestoring force is exerted over the support 323, but the substrate 311has the higher rigidity, and thus the support does not return into theoriginal shape at this stage. In the case of the organic light emittingdiode, the support 323 is generally formed of an encapsulation material,which has functions to suppress the degradation of the EL layer, theanode and the cathode mainly caused by the penetration of external waterand oxygen.

As the first adhesive 322, the reactive curing type, thermosetting type,photo-curing type and anaerobic type of adhesives are named. As thecomposition of the adhesives, any types are fine such as the epoxy type,the acrylate type and the silicon type. However, the organic lightemitting diode is weak to water and oxygen, and thus materials havinghigh barrier properties against water and oxygen are desirable. Such theadhesives are formed by coating, for example. In addition, it is fine tocoat the adhesives over the support or the peeled layers 314 a and 314b. In the embodiment, a UV cure adhesive is used for the first adhesive322. In this case, ultraviolet rays are irradiated, whereby the firstadhesive 322 is cured. The direction of irradiating ultraviolet rays isproperly determined by a person to carry out according to theconfiguration and fabrication method of the organic light emitting diodeand the circuit configuration of the pixel. That is, it is fine toirradiate the ultraviolet rays from either side, from the substrate 311or the support 323. However, the EL layer is generally damaged byirradiating the ultraviolet rays. Therefore, attention is needed to usea light shielding mask for the portions not to be irradiated by theultraviolet rays, or to adjust the energy of the ultraviolet rays tocure only the adhesive, whereby not damaging the other portions.

Then, the substrate 311 disposed with the first material layer 312 ispeeled from the area where the adhesion has been partially reduced, andit is peeled off by a physical unit in the direction of an arrow shownin FIG. 3C. The second material layer 313 has the compressive stress andthe first material layer 312 has the tensile stress, and thus they canbe peeled by a relatively small force (for example, human hands, windpressure blown from a nozzle, and ultrasonic waves).

In this manner, the peeled layers 314 a and 314 b formed over the secondmaterial layer 313 can be separated from the substrate 311. At thisstage, the support 323 returns into the original shape by the restoringforce, and in accordance with this, the layers bonded to the support 323are also curved (FIG. 3D).

Subsequently, as shown in FIG. 3E, a transfer object 351 is bonded tothe second material layer 313 (and the peeled layers 314 a and 314 b)with a second adhesive 352.

As the second adhesive 352, various adhesives of the reactive curingtype, thermosetting type, photo-curing type, and anaerobic type areused. In the embodiment, a UV cure adhesive is used for the secondadhesive 352. The direction of irradiating ultraviolet rays can bedetermined properly by a person to carry out according to theconfiguration and fabrication method of the organic light emitting diodeand the circuit configuration of the pixel. That is, it is fine toirradiate from either side, from the transfer object 351 or support 323.However, as similar to the first adhesive 322, attention is needed touse a light shielding mask for covering the portions not to beirradiated by the ultraviolet rays, or to adjust the energy of theultraviolet rays to cure only the adhesive, whereby not damaging theother portions.

According to the steps, the light emitting device having the peeledlayers 314 a and 314 b over the second adhesive 352 and the transferobject 351 can be fabricated. Such the light emitting device ischaracterized by having a curvature ranging from 50 to 200 cm with noexternal force applied. In addition, the oxide layer 313 to be thesecond material layer is disposed between the second adhesive 352 andthe peeled layer 314 a. The light emitting device thus obtained has thesecond material layer 313 deposited by sputtering and has a slightamount of a rare gas element contained in the second material layer 313.Thus, the overall device can be formed flexible as well. Furthermore,the light emission from the organic light emitting diode can beextracted from the support 323 side, the transfer object 351 side orboth sides. To extract light emission only from the support 323 side iscalled the top face emission or upper emission (also called the topemission). To extract light emission only from the transfer object 352side is called the bottom emission or under emission. To extract lightemission from both sides of the support 323 and the transfer object 352is called the both sides emission or bi-directional emission. In anycase, to extract the light emission of the organic light emitting diodeto the outside, at least one of the support 323 and the transfer object352 needs to be transparent. The light emitting direction can bedetermined properly by a person to carry out according to theconfiguration and fabrication method of the organic light emitting diodeand the circuit configuration of the pixel.

Embodiment 2

In the embodiment, the procedures to fabricate a liquid crystal displaydevice are shown in FIGS. 4A to 4E.

As shown in FIG. 4A, a first material layer 412 is deposited over thesubstrate 411. As the first material layer 412, it may have thecompressive stress or may have tensile stress immediately after filmdeposition. However, it is important to use materials that do notgenerate abnormality in peeling due to annealing in forming the peeledlayer and the irradiation of laser light and have the tensile stress inthe range of 1 to 1×10¹⁰ (Dyne/cm²) after the peeled layer is formed.Typically, nitrides or metals are preferable. A representative exampleis a single layer formed of an element elected from W, WN, TiN and TiW,an alloy material or a compound material having a principal component ofthese elements, or a laminated layer of these. In addition, it is fineto use sputtering for the first material layer 412.

As the substrate 411, glass, silica and ceramics can be used.Furthermore, a semiconductor substrate typically silicon, or a metalsubstrate typically stainless steel may be used. Here, a glass substrate(#1737) having a thickness of 0.7 mm is used.

Subsequently, a second material layer 413 is formed over the firstmaterial layer 412. As the second material layer 413, it is important touse materials that do not generate abnormality in peeling due toannealing in forming the peeled layer and the irradiation of laser lightand have the compressive stress in the range of 1 to 1×10¹⁰ (Dyne/cm²)after the peeled layer is formed. As the second material layer 413,oxides are preferable. A representative example is silicon oxide,silicon oxide nitride and metal oxide materials, or a laminated layer ofthese. Moreover, it is fine to use sputtering to deposit the secondmaterial layer 413. When the second material layer 413 is deposited bysputtering, a rare gas typically argon gas is introduced into a chamberto contain a slight amount of a rare gas element in the second materiallayer 413.

In the first material layer 412 and the second material layer 413, thefilm thickness of each layer is properly set within the range of 1 to1000 nm to adjust the internal stress in the first material layer 412and the internal stress in the second material layer 413.

In addition, in FIGS. 4A to 4E, the embodiment is shown that the firstmaterial layer 412 is formed as contacting with the substrate 411 forsimplifying the processes. However, it is acceptable that an insulatinglayer or metal layer to be a buffer layer is disposed between thesubstrate 411 and the first material layer 412 to enhance the adhesionto the substrate 411.

Then, a peeled layer 414 is formed over the second material layer 413. Apeeled layer 414 a includes TFTs (n-channel TFTs) in the pixel portion,pixel electrodes, retention capacitances, drive circuit TFTs (n-channelTFTs and p-channel TFTs) around the pixel portion, and wiring lines. Inthe embodiment, the reflective liquid crystal display device isconsidered in which only external lights are utilized to obtain lightemission. In this case, it is fine to use metals having highphotoreflectance such as aluminum and silver for the pixel electrode.Furthermore, even though the internal stress in the second materiallayer 413 is varied from the internal stress in the first material layer412, film removal is not generated due to annealing in the fabricationprocess of the peeled layer 414.

Subsequently, an alignment layer is formed over the pixel portion in thepeeled layer 414 and rubbed in one direction. Therefore, the orientationof liquid crystal molecules that will be filled later can be aligned inone direction. After that, pillar or spherical spacers 415 are formed bypatterning or spraying. Accordingly, the thickness of the layer ofliquid crystals that will be filled later can be controlled.

Then, the treatment is performed in which the adhesion of the firstmaterial layer 412 to the second material layer 414 is partiallyreduced. The treatment of partially reducing the adhesion is thetreatment that laser light is partially irradiated onto the secondmaterial layer or the first material layer along the rim of the area tobe peeled, or the treatment that a local pressure is applied fromoutside along the rim of the area to be peeled and the inside orinterface of the second material layer is partially damaged. Morespecifically, it is acceptable that a hard needle is pressed verticallywith a diamond pen and moved with load. Preferably, it is fine that ascriber is used, an amount to press is set from 0.1 to 2 mm and pressureis applied to move the needle. In this manner, it is important to createa portion where the removal phenomenon tends to be generated beforepeeling, that is, to create a trigger. The pretreatment to selectively(partially) reduce the adhesion is performed, whereby defects in peelingare eliminated and the yield is enhanced as well.

Subsequently, as shown in FIG. 4B, an FPC 421 is bonded to a terminalelectrode disposed at the end part of an interconnect wiring lineconnected to the TFTs disposed in the peeled layer 414.

Then, a support 423 is bonded to the substrate 411 (accurately, it isthe oxide layer 413) with sealing agents 422 a and 422 b. However, inorder to fill liquid crystals later, a filling port is disposed as 422a. The support 423 originally having curvature and elasticity is bondedwith the external force applied. After bonded, the restoring force isexerted over the support 423, but the substrate 411 has a higherrigidity. Thus, the support does not return into the original shape atthis stage. The existence of the spacers 415 allows the interval betweenthe support 423 and the substrate 411 to be kept constant. In the liquidcrystal display device, the support 423 is generally the oppositesubstrate, which is considered to have a color filter, a polarizer, acommon electrode and an alignment layer (not shown) formed thereonbeforehand. In the reflective liquid crystal display device, it is fineto use a transparent conductive film (ITO or IZO) for the commonelectrode.

As the sealing agents 422 a and 422 b, the reactive curing type,thermosetting type, photo-curing type and anaerobic type of adhesivesare named. As the composition of the sealing agents, any sealing agentsare fine such as the epoxy type, acrylate type, and silicon type. Theformation of such the sealing agents is performed by coating.Furthermore, it is fine to coat the sealing agents over the support 423side or the substrate 411 side. In the embodiment, a UV cure sealingagent is used for the sealing agent 422. In this case, ultraviolet raysare irradiated, whereby the sealing agent 422 is cured. The direction ofirradiating the ultraviolet rays may be from the support 423 or may befrom the substrate 411. However, attention is needed to use a lightshielding mask for the portions to be damaged by the ultraviolet rays,or to adjust the energy of the ultraviolet rays to cure only the sealingagent, whereby not damaging the other portions.

After that, liquid crystals 424 are filled from the filling port, andthen the filling port is fully sealed with an end-sealing material (notshown). As the composition of the end-sealing material, any end-sealingmaterials are fine such as the epoxy type, acrylate type, and silicontype.

Subsequently, the substrate 411 disposed with the first material layer412 is peeled from the area where the adhesion has been partiallyreduced, and it is peeled by a physical unit in the direction of anarrow shown in FIG. 4C. The second material layer 414 has thecompressive stress and the first material layer 412 has the tensilestress, and thus they can be peeled with a relatively small force (forexample, human hands, wind pressure blown from a nozzle, and ultrasonicwaves).

In this manner, the peeled layer 414 formed over the second materiallayer 413 can be separated from the substrate 411. At this stage, thesupport 423 returns into the original shape by the restoring force, andin accordance with this, the layers bonded to the support 423 are curvedas well (FIG. 4D).

Then, as shown in FIG. 4E, a transfer object 451 is bonded to the secondmaterial layer 413 with an adhesive 452. As the adhesive 452, variousadhesives of the reactive curing type, thermosetting type, photo-curingtype, and anaerobic type are used. In this embodiment, a UV cureadhesive is used for the adhesive 452. It is fine to irradiateultraviolet rays from either side, from the transfer object 451 or thesupport 423. However, attention is needed to use a light shielding maskfor the portions not to be irradiated by the ultraviolet rays, or toadjust the energy of the ultraviolet rays to cure only the adhesive,whereby not damaging the other portions.

According to the steps described above, the liquid crystal displaydevice having the peeled layer 414 over the second adhesive 452 and thetransfer object 451 can be fabricated. Such the semiconductor device ischaracterized by having a curvature of 50 to 200 cm with no externalforce applied. Moreover, the oxide layer 413 to be the second materiallayer is disposed between the adhesive 452 and the peeled layer 414. Theliquid crystal display device thus obtained has the second materiallayer 413 deposited by sputtering and has a slight amount of a rare gaselement contained in the second material layer 413. The overall devicecan be formed flexible as well.

Besides, in the embodiment, the reflective liquid crystal display deviceis considered, and thus the light emission can be obtained from thesupport 423 side. To this end, the support 423 needs to be transparent.

Embodiment 3

In the embodiment, FIG. 5 shows an apparatus for fabricating a lightemitting device having an organic light emitting diode. In addition, theapparatus shown in the embodiment allows fabricating the light emittingdevice shown in the embodiment 1.

FIG. 5 shows an apparatus for depositing a light emitting layer (ELlayer) of the organic light emitting diode by the dry deposition methodof low weight molecular organic compounds. The apparatus is mainlyconfigured of transport chambers for transferring substrates, deliverychambers for delivery, deposition chambers for depositing various thinfilms, and an encapsulation chamber for encapsulation. Each chamber isequipped with an exhaust system for achieving necessary vacuum degreesor a system for generating a gas atmosphere such as N₂. In addition, theseparate chambers are connected by gate valves. The substrates aretransferred by transfer robots.

First, a substrate 501 c necessary to fabricate an organic lightemitting diode, which has been formed with a pixel portion, a drivecircuit part, wiring lines, electrodes and a protection film beforehand,is introduced into a delivery chamber 500 from outside. Typically, TFTsare used for the pixel portion and the drive circuit part.

The substrate 501 c introduced into the delivery chamber 500 is carriedto a transport chamber 501 a by a transfer robot 501 b and furthercarried to a pretreatment chamber 502. Typically, the substrate 501 c isheated or undergoes pretreatment such as O₂ plasma processing in thepretreatment chamber 502. The pretreatment is intended to enhancevarious characteristics of the organic light emitting diode.

The substrate after the pretreatment is carried to a transport chamber504 through a delivery chamber 503. The transport chamber 504 is alsoinstalled with a transfer robot serving to transfer substrates to theseparate chambers connected to the transport chamber 504. The transportchamber 504 is connected to deposition chambers for depositing organiclayers. In consideration of fabricating a display device having anorganic light emitting diode of full color display, provided aredeposition chambers 506R, 506G and 506B for forming light emittinglayers of red, green and blue, and a deposition chamber 505 fordepositing common layers for each color, that is, a carrier transportlayer and a carrier injection layer. In these deposition chambers,vacuum evaporation is used in general. To obtain full color emission, itis acceptable to use a shadow mask for separately applying colors forevaporation so as to arrange the light emitting layers expressing thered, green and blue colors in stripes, mosaics or delta shapes.

The substrate after the deposition of the organic layers is carried to atransport chamber 508 through a delivery chamber 507. The transportchamber 508 is also installed with a transfer robot for serving totransfer substrates to each chamber connected to the transport chamber508. The transport chamber 508 is connected to deposition chambers forforming a backside electrode and protection films. In depositionchambers 509 and 510, metals (such as AlLi alloy or MgAg alloy) to beelectrodes are deposited by vacuum evaporation and electron beamevaporation. In a deposition chamber 511, a transparent conductive film(such as ITO or IZO) necessary to obtain light emission from the topface of the substrate is deposited by sputtering or chemical vapordeposition (CVD) in general. In a deposition chamber 512, a passivationfilm (such as SiN and SiOx films) for protecting the surface isdeposited by sputtering or CVD in general.

The substrate after the deposition is carried to a transport chamber 514through a delivery chamber 513. The transport chamber 514 is connectedto a plurality of chambers necessary for encapsulation. The transportchamber 514 is also installed with a transfer robot for serving totransport substrates or encapsulation substrates to each chamberconnected to the transport chamber 514.

First, substrates for encapsulation need to be prepared. The chambersfor the purpose are an encapsulation glass substrate preparation chamber515 a and an encapsulation plastic substrate preparation chamber 515 b.

To the encapsulation glass substrate preparation chamber 515 a, anopposite glass for encapsulating the fabricated organic light emittingdiode with glass is introduced from outside. A desiccant for protectingthe organic light emitting diode against water can be introduced intothe opposite glass as necessary. For example, it is fine to bond asheet-shaped desiccant to the spot-faced recess of the opposite glasswhere spot facing has been applied beforehand with a double-face tape.

In the meantime, in the encapsulation plastic substrate preparationchamber 515 b, encapsulation is prepared for encapsulating thefabricated organic light emitting diode with plastic. It is fine tointroduce a plastic (finished product) having a shape matched to thepurpose from outside. In the embodiment, however, a support (it isplastic in the embodiment) of the invention is fabricated in theencapsulation plastic substrate preparation chamber 515 b. For example,the support with curvature and elasticity is fabricated according to thematerials and methods described by FIGS. 2A and 2B. More specifically,the molds 211 a and 211 b and the thermosetting resin 212 are introducedfrom outside for shaping such as heating, pressing and cooling. When theorganic light emitting diode is transferred onto a plastic, it is fineto fabricate the transfer object in the invention as well in the similarmanner. The work may be fully automated or may be partially manuallyoperated by disposing gloves.

The prepared encapsulation glass substrate or encapsulation plasticsubstrate is carried to a dispenser chamber 516 and an adhesive (notshown) for bonding it to a substrate later is applied. In theembodiment, an adhesive of the UV curable type is used for the adhesive.Furthermore, a desiccant for protecting the organic light emitting diodefrom water (not shown) may be disposed in the dispenser chamber 516 notin introducing the glass substrate into the encapsulation glasssubstrate preparation chamber 515 a. For example, a sheet-shapeddesiccant can be bonded to the spot-faced recess of the opposite glasswhere spot facing has been applied with a double-face tape. Accordingly,the desiccant does not need to be handled in the atmosphere. As for thework, it may be fully automated or may be partially manually operated bydisposing gloves. Particularly, when the encapsulation plastic substratehas curvature and elasticity, the adhesive may be coated with thesubstrate curved or may be coated with it stretched straight.

The substrate after deposition and the encapsulation glass substrate orencapsulation plastic substrate coated with the adhesive are carried toan encapsulation chamber 517, and they are bonded to each other. It isnecessary to use a proper jig (not shown) to press them in bonding. Itis fine to bond the encapsulation plastic substrate with curvature andelasticity with it stretched straight. As for the work, it may be fullyautomated or may be partially manually operated by disposing gloves.

Subsequently, the substrate and the encapsulation substrate, which havebeen bonded to each other in the encapsulation chamber 517, are carriedto a UV irradiation chamber 518 and ultraviolet rays for curing theadhesive are irradiated onto them.

It is fine to bring the substrate and the encapsulation substrate out ofa delivery chamber 519 to outside, which have been bonded in the UVirradiation chamber 518.

However, when the device in the invention is fabricated, two steps arefurther needed, removing the substrate and bonding the transfer objectas shown in FIGS. 1D and 1E. More specifically, the substrate and theencapsulation substrate (support), which have been bonded in the UVirradiation chamber 518, are again brought back to the encapsulationplastic substrate preparation chamber 515 b. The substrate is peeled inthe encapsulation plastic substrate preparation chamber 515 b. In theembodiment, the method of utilizing the membrane stress between themetal layer or nitride layer and the oxide layer is used for the peelingmethod. In the meantime, as similar to the support, the transfer objectis carried to the dispenser chamber 516 from the encapsulation plasticsubstrate preparation chamber 515 b, and the adhesive is applied to it.The support peeled off the substrate and the transfer object coated withthe adhesive are carried to the encapsulation chamber 517, and they arebonded to each other. After that, they are carried to the UV irradiationchamber 518 for UV irradiation, whereby the display device is completed.Finally, it is fine to bring the finished product out of the deliverychamber 519 to outside.

Besides, the embodiment can be combined with the embodiment 1.

Embodiment 4

The embodiment shows the example of installing the display withcurvature obtained by the invention on a vehicle. Here, an automobilewas used as a typical example of the vehicles, but the invention is notlimited particularly, without saying that it can be adapted toaircrafts, trains and electric railcars.

FIG. 6 is a diagram illustrating around the driver seat of anautomobile. In a dashboard part, audio systems, specifically a car audiosystem and a navigation system, are disposed. A main body 2701 of thecar audio system includes a display part 2702, and operating switches2703 and 2704. The invention is implemented to the display part 2702,whereby a low-profile, light-weight car audio system can be completed.In addition, the invention is implemented to a display part 2801 of thecar navigation system, whereby a low-profile, light-weight carnavigation system can be completed.

Furthermore, near an operating handle part 2605, a display part 2603 fordigital display of meters such as a speedmeter is formed on thedashboard part 2601. The invention is implemented to the display part2702, whereby a low-profile, light-weight display for meters can becompleted.

Moreover, it is fine to form a display part 2602 bonded to the dashboardpart 2601 with a curved surface. The invention is implemented to thedisplay part 2602, whereby a low-profile, light-weight display formeters or image display device can be completed. Besides, the displaypart 2602 is curved in the directions indicated by arrows.

In addition, it is fine to form a display part 2600 bonded to anautomobile windshield 2604 with a curved surface. When the invention isimplemented to the display part 2600, it is acceptable to usetransparent materials. The invention allows completing a low-profile,light-weight display for meters or image display device. Furthermore,the display part 2600 is curved in the directions indicated by arrows.Here, the automobile windshield is exemplified, but the display part canbe disposed over the other window glasses.

For example, it is fine to form a display part 2902 bonded to a rearwindow 2900 with a curved surface. FIG. 7 is a diagram illustratingaround the back seat of the automobile. Moreover, FIG. 7 corresponds toFIG. 6, and the operating handle part is the same, thus using the samereference numerals and signs as those in FIG. 6.

In addition, when a flexible display device of the invention is bondedto the rear window 2900 and a camera capable of shooting backside ismounted outside the car to connect them each other, a driver can seeplaces where an automobile body 2906 hinders the driver from seeing.Furthermore, the display part 2902 is curved in the directions indicatedby arrows.

Moreover, as shown in FIG. 7, when the car is right-handled, a deadangle exists left backside because a part of the automobile body 2906 (aportion between window glasses) is there. However, when the displaydevice of the invention (a display part 2901) is bonded to the portionbetween the window glasses and a camera capable of shooting thedirection of the dead angle is mounted outside the car to connect themeach other, the driver can confirm the dead angle. Besides, the displaypart 2901 is curved in the directions indicated by arrows.

In addition, it is acceptable to dispose a display part 2905 over a seat2904. A person seated in the back seat can watch the television or cansee the display of the car navigation system.

Furthermore, as not shown in the drawing here, a car ceiling is formedof a base material to bond a display device having an organic lightemitting diode with a shape matched with the curved surface of theceiling, whereby allowing image display or lighting the inside of thecar.

In this manner, the display with a curved surface of the invention canbe installed easily anywhere in the car with curved surfaces having acurvature radius of 50 to 200 cm.

Moreover, the embodiment shows the displays for the car audio system andthe car navigation system for automobile use, but they can be used fordisplays for other vehicles or floor audio systems and navigationsystems.

Besides, the embodiment can be combined with the embodiments 1 and 2.

Embodiment 5

In the embodiment, devices and the peripheral structure contained in thepeeled layer are shown. Here, the cross-sectional structure of a singlepixel in the active matrix display device, particularly the connectionbetween a light emitting device and a TFT, and the form of a separatordisposed between pixels will be described.

In FIG. 8A, reference numeral 40 denotes a substrate, reference numeral41 denotes a separator (also called a bank), reference numeral 42denotes an insulating film, reference numeral 43 denotes a firstelectrode (anode), reference numeral 44 denotes a layer including anorganic compound, reference numeral 45 denotes a second electrode(cathode), and reference numeral 46 denotes a TFT.

In the TFT 46, 46 a denotes a channel forming region, reference numeral46 b and reference numeral 46 c denote a source region or drain region,reference numeral 46 d denotes a gate electrode, and reference numeral46 e and reference numeral 46 f denote a source electrode or drainelectrode. A top gate TFT is shown here, but the TFT is not definedparticularly, it may be an inversely staggered TFT or may be a staggeredTFT. In addition, reference numeral 46 f is the electrode that ispartially overlapped with the first electrode 43, whereby connecting itto the TFT 46.

Furthermore, FIG. 8B shows the cross-sectional structure partlydifferent from that in FIG. 8A.

In FIG. 8B, the manner to overlap the first electrode with the electrodeis varied from the structure shown in FIG. 8A. The first electrode ispatterned and then the electrode is formed so as to partially overlapwith the first electrode, whereby connecting to the TFT.

Moreover, FIG. 8C shows the cross-sectional structure partly differentfrom that in FIG. 8A.

In FIG. 5C, one layer of an interlayer dielectric is further disposed,and a first electrode is connected to the electrode of a TFT through acontact hole.

Besides, as the cross-sectional form of the separator 41, it may beformed into a tapered shape as shown in FIG. 8D. The separator can beobtained in which a resist is exposed by the photolithographic techniqueand then a non-photosensitive organic resin or inorganic insulating filmis etched.

In addition, when a positive photosensitive organic resin is used, theshape shown in FIG. 8E can be formed, the shape having a curved surfacein the upper end part.

Furthermore, when a negative photosensitive organic resin is used, theshape shown in FIG. 8F can be formed, the shape having a curved surfacein the upper end part and the lower end part.

Moreover, the embodiment can be combined with any of the embodiments 1,3 and 4.

Embodiment 6

The embodiment shows an example of fabricating a passive matrix lightemitting device (also called a simple matrix light emitting device).

First, over a substrate, a plurality of first wiring lines is formed instripes with a material such as ITO (a material to be an anode).Subsequently, a separator made of a resist or photosensitive resin isformed as surrounding the area to be a light emitting area. Then, alayer containing organic compounds is formed in the area surrounded bythe separator by evaporation or ink jet printing. When a full colordisplay is formed, materials are properly selected to form the layercontaining the organic compounds. After that, over the separator and thelayer containing the organic compounds, a plurality of second wiringlines in stripes is formed with a metal material such as Al or Al alloy(a material to be a cathode) so as to cross the plurality of firstwiring lines formed of ITO. According to the steps described above, thepeeled layer containing the light emitting diode forming the layercontaining the organic compounds into the light emitting layer can befabricated.

Subsequently, an encapsulation substrate to be the support is bondedwith a sealing material. Alternatively, a protection film is disposedover the second wiring lines for encapsulation.

Then, the substrate is peeled and the peeled layer containing the lightemitting diode is bonded to the transfer object (for example, a glasssubstrate with a curved surface). The method for peeling the substrateis not defined particularly. It is fine to use the methods shown in theembodiment mode and the embodiment 1 are used.

In addition, the invention can be implemented not only to the full colordisplay device but also to a monochromatic light emitting device, suchas a surface light source and an illumination system.

Furthermore, the embodiment can be freely combined with the embodiments1, 3, 4, and 5.

According to the invention, displays can be installed in variousportions with a curved surface (including windows, ceilings, doors anddashboards) in the limited space, such as the driver seat of vehicles,typically automobiles and aircrafts.

1. A method for fabricating a light emitting device comprising a layercontaining a light emitting element, the method comprising: forming alayer containing a thin film transistor over a first substrate; formingthe layer containing the light emitting element over the layercontaining the thin film transistor; bonding a second flexible substrateto the layer containing the light emitting element; peeling the layercontaining the thin film transistor and the layer containing the lightemitting element bonded with the second flexible substrate from thefirst substrate; and bonding a third flexible substrate to the layercontaining the thin film transistor to sandwich the layer containing thethin film transistor and the layer containing the light emitting elementbetween the second flexible substrate and the third flexible substrate.2. The method for fabricating the light emitting device according toclaim 1, wherein the second flexible substrate comprises plastic.
 3. Themethod for fabricating the light emitting device according to claim 1,wherein the second flexible substrate to be bonded to the layercontaining the light emitting element has curvature.
 4. The method forfabricating the light emitting device according to claim 1, wherein thethird flexible substrate comprises plastic.
 5. The method forfabricating the light emitting device according to claim 1, furthercomprising: applying the light emitting device to a display portion. 6.The method for fabricating the light emitting device according to claim1, further comprising: attaching the light emitting device to a mainbody, a window, or a seat of a vehicle.
 7. The method for fabricatingthe light emitting device according to claim 1, further comprising:attaching the light emitting device to a main body, a window, adashboard part, an automobile body or a seat of an automobile.
 8. Amethod for fabricating a light emitting device comprising a layercontaining a light emitting element, the method comprising: forming alayer containing a thin film transistor over a first substrate; formingthe layer containing the light emitting element over the layercontaining the thin film transistor; bonding a second flexible substrateto the layer containing the light emitting element via an adhesive;peeling the layer containing the thin film transistor and the layercontaining the light emitting element bonded with the second flexiblesubstrate from the first substrate; and bonding a third flexiblesubstrate to the layer containing the thin film transistor to sandwichthe layer containing the thin film transistor and the layer containingthe light emitting element between the second flexible substrate and thethird flexible substrate.
 9. The method for fabricating the lightemitting device according to claim 8, wherein the second flexiblesubstrate comprises plastic.
 10. The method for fabricating the lightemitting device according to claim 8, wherein the second flexiblesubstrate to be bonded to the layer containing the light emittingelement has curvature.
 11. The method for fabricating the light emittingdevice according to claim 8, wherein the third flexible substratecomprises plastic.
 12. The method for fabricating the light emittingdevice according to claim 8, further comprising: applying the lightemitting device to a display portion.
 13. The method for fabricating thelight emitting device according to claim 8, further comprising:attaching the light emitting device to a main body, a window, or a seatof a vehicle.
 14. The method for fabricating the light emitting deviceaccording to claim 8, further comprising: attaching the light emittingdevice to a main body, a window, a dashboard part, an automobile body ora seat of an automobile.
 15. A method for fabricating a light emittingdevice comprising a layer containing a light emitting element, themethod comprising: forming a layer containing at least one selected frommetal, oxide, and nitride over a first substrate; forming a layercontaining a thin film transistor over the layer containing the at leastone selected from metal, oxide, and nitride; forming the layercontaining the light emitting element over the layer containing the thinfilm transistor; bonding a second flexible substrate to the layercontaining the light emitting element; peeling the layer containing thethin film transistor and the layer containing the light emitting elementbonded with the second flexible substrate from the first substrate; andbonding a third flexible substrate to the layer containing the thin filmtransistor to sandwich the layer containing the thin film transistor andthe layer containing the light emitting element between the secondflexible substrate and the third flexible substrate.
 16. The method forfabricating the light emitting device according to claim 15, wherein thesecond flexible substrate comprises plastic.
 17. The method forfabricating the light emitting device according to claim 15, wherein thesecond flexible substrate to be bonded to the layer containing the lightemitting element has curvature.
 18. The method for fabricating the lightemitting device according to claim 15, wherein the third flexiblesubstrate comprises plastic.
 19. The method for fabricating the lightemitting device according to claim 15, further comprising: applying thelight emitting device to a display portion.
 20. The method forfabricating the light emitting device according to claim 15, furthercomprising: attaching the light emitting device to a main body, awindow, or a seat of a vehicle.
 21. The method for fabricating the lightemitting device according to claim 15, further comprising: attaching thelight emitting device to a main body, a window, a dashboard part, anautomobile body or a seat of an automobile.
 22. A method for fabricatinga light emitting device comprising a layer containing a light emittingelement, the method comprising: forming a layer containing a thin filmtransistor over a first substrate; forming a layer containing the lightemitting element over the layer containing the thin film transistor;bonding a second flexible substrate to the layer containing the lightemitting element via a first adhesive; peeling the layer containing thethin film transistor and the layer containing the light emitting elementbonded with the second flexible substrate from the first substrate; andbonding a third flexible substrate to the layer containing the thin filmtransistor via a second adhesive to sandwich the layer containing thethin film transistor and the layer containing the light emitting elementbetween the second flexible substrate and the third flexible substrate.23. The method for fabricating the light emitting device according toclaim 22, wherein the second flexible substrate comprises plastic. 24.The method for fabricating the light emitting device according to claim22, wherein the second flexible substrate to be bonded to the layercontaining light emitting element has curvature.
 25. The method forfabricating the light emitting device according to claim 22, wherein thethird flexible substrate comprises plastic.
 26. The method forfabricating the light emitting device according to claim 22, furthercomprising: applying the light emitting device to a display portion. 27.The method for fabricating the light emitting device according to claim22, further comprising: attaching the light emitting device to a mainbody, a window, or a seat of a vehicle.
 28. The method for fabricatingthe light emitting device according to claim 22, further comprising:attaching the light emitting device to a main body, a window, adashboard part, an automobile body or a seat of an automobile.
 29. Amethod for fabricating a light emitting device comprising a layercontaining a light emitting element, the method comprising: forming alayer containing at least one selected from metal, oxide, and nitrideover a first substrate; forming a layer containing a thin filmtransistor over the layer containing the at least one selected frommetal, oxide, and nitride; forming the layer containing the lightemitting element over the layer containing the thin film transistor;bonding a second flexible substrate to the layer containing the lightemitting element via a first adhesive; peeling the layer containing thethin film transistor and the layer containing the light emitting elementbonded with the second flexible substrate from the first substrate; andbonding a third flexible substrate to the layer containing the thin filmtransistor via a second adhesive to sandwich the layer containing thethin film transistor and the layer containing the light emitting elementbetween the second flexible substrate and the third flexible substrate.30. The method for fabricating the light emitting device according toclaim 29, wherein the second flexible substrate comprises plastic. 31.The method for fabricating the light emitting device according to claim29, wherein the second flexible substrate to be bonded to the organiclight emitting layer has curvature.
 32. The method for fabricating thelight emitting device according to claim 29, wherein the third flexiblesubstrate comprises plastic.
 33. The method for fabricating the lightemitting device according to claim 29, further comprising: applying thelight emitting device to a display portion.
 34. The method forfabricating the light emitting device according to claim 29, furthercomprising: attaching the light emitting device to a main body, awindow, or a seat of a vehicle.
 35. The method for fabricating the lightemitting device according to claim 29, further comprising: attaching thelight emitting device to a main body, a window, a dashboard part, anautomobile body or a seat of an automobile.
 36. A method for fabricatinga light emitting device comprising a layer containing a light emittingelement, the method comprising: forming a layer containing a thin filmtransistor over a first substrate; forming the layer containing thelight emitting element over the layer containing the thin filmtransistor; bonding a second flexible substrate to the layer containingthe light emitting element; peeling the layer containing the thin filmtransistor and the layer containing the light emitting element bondedwith the second flexible substrate from the first substrate; and bondinga third flexible substrate to the layer containing the thin filmtransistor via an adhesive to sandwich the layer containing the thinfilm transistor and the layer containing the light emitting elementbetween the second flexible substrate and the third flexible substrate.37. The method for fabricating the light emitting device according toclaim 36, wherein the second flexible substrate comprises plastic. 38.The method for fabricating the light emitting device according to claim36, wherein the second flexible substrate to be bonded to the layercontaining the light emitting element has curvature.
 39. The method forfabricating the light emitting device according to claim 36, wherein thethird flexible substrate comprises plastic.
 40. The method forfabricating the light emitting device according to claim 36, furthercomprising: applying the light emitting device to a display portion. 41.The method for fabricating the light emitting device according to claim36, further comprising: attaching the light emitting device to a mainbody, a window, or a seat of a vehicle.
 42. The method for fabricatingthe light emitting device according to claim 36, further comprising:attaching the light emitting device to a main body, a window, adashboard part, an automobile body or a seat of an automobile.
 43. Amethod for fabricating a liquid crystal display device comprising aliquid crystal layer, the method comprising: forming a layer containinga thin film transistor over a first substrate; bonding a second flexiblesubstrate to the layer containing the thin film transistor; forming aliquid crystal layer between the layer containing the thin filmtransistor and the second flexible substrate; peeling the liquid crystallayer bonded with the second flexible substrate from the firstsubstrate; and bonding a third flexible substrate to the layercontaining the thin film transistor to sandwich the layer containing thethin film transistor and the liquid crystal layer between the secondflexible substrate and the third flexible substrate.
 44. The method forfabricating the liquid crystal display device according to claim 43,wherein the second flexible substrate comprises plastic.
 45. The methodfor fabricating the liquid crystal display device according to claim 43,wherein the second flexible substrate to be bonded to the liquid crystallayer has curvature.
 46. The method for fabricating the liquid crystaldisplay device according to claim 43, wherein the third flexiblesubstrate comprises plastic.
 47. The method for fabricating the liquidcrystal display device according to claim 43, further comprising:attaching the liquid crystal display device to a main body, a window, ora seat of a vehicle.
 48. The method for fabricating the liquid crystaldisplay device according to claim 43, further comprising: attaching theliquid crystal display device to a main body, a window, a dashboardpart, an automobile body or a seat of an automobile.